* {
    margin: 0;
    padding: 0;
}
html,
body {
    height: 100%;
    position: relative;
    width: 100%;
}
body {
    background: #eee;
}
canvas {
    background: white;
    display: block;
}
#c {
    left: 50%;
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
}